Rena, an 11-year-old girl residing in Neo Tokyo, stands as a central human protagonist and close friend of Kaito. She actively aids the Dino Knights against the Dragozaurs, who threaten Earth's life force. Her intelligence, resourcefulness, and courage frequently emerge through quick thinking in dangerous scenarios. Rena wields advanced technical skills, particularly in hacking and technology comprehension, exceeding typical adult capabilities; these enable effective operation of computers and gadgets during missions. Multilingual, she occasionally translates enemy communications. She exhibits a protective and assertive personality, exemplified early when defending Kaito from a bully by challenging the aggressor to an arm-wrestling match. However, impulsiveness surfaces during an African trip where she leaps into a river despite being unable to swim, necessitating Kaito's rescue—later reframed by her as intentional. Her role evolves from initial involvement to a trusted ally and Secret-Keeper alongside Kaito and Rick after learning of the Dino Knights. Throughout conflicts, she delivers strategic support and advances team objectives using technical expertise. Her established traits and supportive role remain consistent across all official media, including OVAs and franchise extensions.